Conventionally, Japanese Unexamined Patent Publication No. 63-187960/1988 (Tokukaisho 63-187960) discloses a communication adapter for personal computer (i.e., PC) communication in PC and facsimile (i.e., FAX) communication via a common public telephone line (i.e., telephone line).
The communication adapter has an automatic receiving device connected to the telephone line, and a first terminal which connects the PC to the automatic receiving device. The automatic receiving device automatically performs a sequential operation for receiving data via the telephone line.
The communication adapter has a second terminal connected to the FAX, and a switching device which connects the second terminal to the telephone line based upon an identifying (i.e., ID) signal representing FAX communication included in the received data.
In such a communication adapter, when the ID signal is detected by the automatic receiving device at the time of FAX communication from the telephone line, the switching device intermittently connects the FAX to the telephone line via the second terminal based upon the ID signal. As a result, data can be automatically received via the communication adapter by selectively connecting one telephone line to the PC or FAX.
However, in the above conventional arrangement, since the FAX is connected to the PC so as to be used as a scanner or a printer of the PC, not only the usual operation for FAX communication but also an operation by a user for selecting a switch are required. Therefore, there arises such a problem that the data communication is complicated.
In addition, in the above conventional arrangement, in order to use the FAX as a scanner or a printer of PC, a certain connecting function is required for connecting FAX to PC. For example, a data converting function such as RS232C is required on the FAX side for connecting the FAX to the PC. Moreover, in the case where protocol used for data communication with PC is controlled by software on the FAX side, the burden of the software is increased. As a result, there arises a problem that the cost of the FAX rises dependent on connecting functions and software.